Use RSP file for long classpaths

Setting use_resource_processor: true can increase the length of the
classpath enough to trigger "command line too long" errors.  There are
clockwork libraries with 546 transitive android_library dependencies.
Write classpaths longer than 64kB to a separate file and add them
to the javac and turbine command lines with the @file syntax.

Bug: 294256649
Test: m checkbuild
Change-Id: I2b6a57ae30de03347db3221e9c9a4b2efb490115